Positioning control means for web striping device



Jan. 5, 1960 A. "r. WILLIAMS ETAL 2,919,673

POSITIONING CONTROL MEANS FOR WEB STRIPING DEVICE Filed March 16, 1959 42 Sheets-Sheet 1 mmvrozes.

ARTHUR T. WILLIAMS 2 CHARLES ROBERT TIDLAND' ZTTORNEY Jan. 5, 1960 A. T.WILLIAMS ETAL 2,919,673

POSITIONING CONTROL MEANS FOR was STRIPING mivrca 2 Sheets-Sheet 2 FiledMarch 16, 1959 INVENTORS.

ARTHUR T WILLIAMS CHARLES ROBERT BY TlDLAND I v I A TORNEY POSITIONINGCONTROL MEANS FOR WEB STRIPING DEVICE Arthur T. Williams, Washougal, andCharles Robert Tidland, Camas, Wash.

Application March 16, 1959, Serial No. 799,758

4 Claims. (Cl. 118-8) This invention relates in general to thepositioning of devices designed to operate on a traveling web where itis desired to maintain such a device operating constantly at an exactpredetermined distance from one edge of the web.

In particular, the invention relates to the positioning of such a deviceas a glue applicator operating along the edge of a traveling web ofpaper, when, for example, the web of paper is being rapidly fed into abag making machine. As is well known, in paper bag machines the paperweb is first formed into a tube by applying a narrow line of adhesivealong one edge of the web and then folding the edges towards each otheruntil one edge overlies the other with a line of adhesive between them.The narrow line of adhesive is applied a very slight distance in fromone edge of the paper web so that in the forming of the tube theadhesive will not be squeezed beyond the edge of the web to which it isapplied, since this would cause some of the adhesive to spread beyondthe bag seam and result in getting adhesive on the pressing rolls andalso in causing the final bags to be stuck together. Similarly the otheredge of the web extends slightly beyond the line of adhesive when thetube is formed so that the adhesive will not be squeezed beyond thisother edge of the web. Furthermore, in order to avoid waste of material,it is desirable that the extent to which one edge of the web is made tooverlie the other should be limited to a distance suficient to cover thead hesive strip completely and safely but without too much excess.Since, in a rapidly traveling web of material, such as a web of paperbeing delivered from a supply roll to a high speed bag machine, therewill invariably be some slight fluctuations in the position of the edgesof the traveling web, it is necessary to have the device which appliesthe thin line of adhesive continuously to the web so arranged that itwill follow any slight lateral movements in the web edge and thusconstantly maintain its desired position relative to the web edge.

The object of the present invention is to provide practical controlmeans by which a device operating on a traveling web, especially adevice applying a strip of adhesive adjacent one edge of the web, willautomatically be maintained in a predetermined position with respect tothe web edge.

A related object of the invention is to provide such an automaticcontrol which will be simple in construction, positive and direct in itsoperation, and which will present no particular problem of maintenance.

The manner in which these objects and other incidental advantages areobtained, and the construction and method of operation of this improvedautomatic positioning control, will be readily understood from thefollowing brief description with reference to the accompanying drawings.

In the drawings:

Fig. 1 is a foreshortened fragmentary sectional elevation of a portionof the web feeding assembly for a paper bag machine, the sectionalelevation being taken transversely with respect to the assembly andtravel of the web, showing the glue applicator for the web and thepositioning control means for the applicator, this section being takento the left of Fig. 2;

Fig. 2 is a fragmentary sectional sideelevation taken on line 22 of Fig.l, but drawn to a smaller scale; and

Fig. 3 is a fragmentary section taken on the line indicated at 33 inFig. l, but drawn to the same scale as Fig. 2.

In the figures, 10 indicates the web of paper which is traveling in thedirection indicated by the arrows in Fig. 2 and which passes over thehorizontal guide rollers 11, 12, 13 and 14 in succession immediatelybefore being formed into a tube in the bag making machine (the tubeforming portion and remainder of the bag machine not being shown in thedrawings). The guide rollers are rotatably supported in a framestructure indicated in general at 15.

A horizontal shaft 16 is supported on the frame structure 15 and ismounted parallel to the axes of the guide rollers for the traveling web.This shaft 16 is located preferably, but not necessarily, below thetopmost guide roller 14. This shaft 16 is mounted in suitable bearingsso as to be slidable longitudinally or in an axial direction. A collar17 (Figs. 1 and3) is adjustably secured near one end of the shaft 16beyond the side of the frame structure 15 on which the bearing for thatend of the shaft is secured, and a coil spring 18 is held on the shaft16 with its ends engaged by the side of the frame structure 15 and bythe collar 17 respectively. The extreme end of the slidable shaft 16 isbifurcated to accommodate the end of a lever arm 19 which is pivotallyconnected to the shaft 16 by a pivot bolt 20. The lever arm 19 extendsdownwardly from the shaft 16 and the bottom end of this lever arm ispivotally mounted on a stationary bracket 21 (Fig. 1) secured to theframe structure. The aperture in the upper end of the lever arm 19 for.

the pivot bolt 20 is slightly elongated longitudinally with.

respect to the lever arm so as to allow for the slight arcuate travel ofthe upper end of the lever arm 19 with the sliding movement of the shaft16 without imposing any bind on the shaft 16.

A dish-shaped casing 22 (Fig. 1), so arranged as to form a housing for acircular diaphragm chamber, is secured on the frame structure 15 betweenthe shaft 16 and the bracket 21 for the lower end of the arm 19, andthis housing is so positioned that the lever arm 19 will lie in a planepassing substantially through the axial center of the circular diaphragmchamber. A flexible diaphragm 23 is secured to the outer wall of thediaphragm chamber housing by means of a ring 24 and screws 25. A bar 26,has a reduced, round and threaded end portion 27 which extends throughan aperture in the center of the diaphragm 23 and through a pair ofclamping discs 28 and 29, which discs are located on the outside and onthe inside of the diaphragm respectively, and a clamping nut 30 securesthis end of the bar 26 together with the companion clamping discstightly to the diaphragm 23. The other or outer end of the bar 26 isbifurcated and is pivotally connected to the lever arm 19 by means ofthe bolt 32, the aperture in the lever arm 19 for the bolt 32 beingslightly elongated longitudinally the same as is the aperture for thebolt 20.

As will be apparent from Fig. 1, the arrangement is such that vacuumsuction in the diaphragm chamber, acting on the diaphragm 23, will causethe bar 26, and with it the lever arm 19 and shaft 16, to move towardsthe left as viewed in Fig. l, causing the shaft 16 to be moved inopposition to the force of the spring 18; while, upon reduction of thevacuum suction in the diaphragm chamber, the spring 18 will combine withthe diaphragm in causing the shaft 16, the lever arm 19 and bar 26 who;

moved in the opposite direction or towards the right. Thus the assemblyis so arranged that fluctuation of the vacuum suction in the diaphragmchamber will produce longitudinal movement of the shaft 15. Thediaphragm chamber is connected to a vacuum pump (not shown) or mothersuitable constantly operating air exhaust means by the tube 33.

A box-like sensing head 34 is firmly but adiustably secured on the endof a rigid support arm which in turn is rigidly held in a mountingcollar 36. The collar 36 is firmly but adjustably secured on the shaftid. Consequently this sensing head 34 will be moved laterally wheneverthe shaft 16 is moved longitud nally and will be moved-exactly to thesame extent as the shaft 16. The sensing head 34 has a hollow interiorwhich is connected with the diaphragm chamber 22 by a flexible air hose37.

-'This sensing head 34 is provided with one or more small orifices 35through which air can be drawn into the interior of the head and thencedrawn through the hose 37 into the diaphragm chamber. The sensing headis so arranged and positioned that t e traveling web ll) will move overthe face of the sensing head in which these orifices 33 are located. Theorifices are arranged in alignment with the direction of travel of theweb ll). in the preferred arrangement shown in Fig. l, the sensing headis provided with three of these orifices all of which are in alignmentwith the direction of travel of the web over the sensing head, and thesensing ead is so positioned that the edge of the web under properoperating conditions will be in registration with the center line ofthese three orifices. The reason for this will presently be apparent.

The adhesive or glue, which is deposited along near one edge of the webof paper preparatory to the forming of the paper web into a tube in apaper bag machine, is customarily delivered under pressure through adistributing nozzle. In Figs. 2 and 3 such glue-applying nozzle isindicated by the reference character 59. The adhesive or glue isdelivered to the nozzle head under pressure through the flexible tube 40from a suitable source (not shown). As is customary, the discharging endof this nozzle is positioned very close to the traveling web so that theglue can be delivered onto the web in a desired continuous narrowdefined line, and the rate at which the glue is discharged from thenozzle is regulated in accordance with the speed of the traveling web sothat a uniform glue line, with neither too much nor too little glue onany part of the line, will result.

In the carrying out of the present invention the nozzle head issupported on a rigid arm 41 wh ch is firmly but adjustablv secured in acollar 42, and this collar 42 in turn is firmly but adjustably securedon the shaft 16. Consequently any movement of the shaft 1%, in an axialdirection, will result in lateral movement of the glueapplying nozzlewith respect to the direction of the travel. of the web 10. Thus thenozzle 3'9. the sensing head 34 and the shaft 16 all move in unison,whenever any movement of these members with respect to the traveling Webtakes place.

In the operation of this positioning control assembly the withdrawal ofair from the diaphragm chamber through the tube 33 by the vacuum pump isadjusted so as to equal the rate at which the air will be drawn into thediaphragm chamber through the orifices 38 in the sensing head 34 andthrough the connecting tube 37 when the edge of the paper web passesexactly over the center line of the orifices. In other words, when theorifices 38 are left half open by the paper web as it passes over thesensing head, the assembly will be in balance and the shaft 16, and withit the sensing head 34 and the glue-applying nozzle. will be stationary.Should the edge of the web shift slightly to the right (as viewed inFigs. 1 and 3),'causing the orifices 38 to be entirely uncovered, thenair will momentarily be drawn into the diaphragm chamber more rapidlythan itis 'exhaustedqby the vacuum pump. This reduction of the suctionpressure on the diaphragm, together with the force of the spring 18(which is at all times under some pressure) will cause the shaft 16 (andwith it the sensing head and the glueapplying nozzle) to move to theright. However, should this movement to the right be sufficient to causethe edge of the paper web to cover the orifices 3% completely, therebytemporarily substantially shutting off any delivery of air into thediaphragm chamber, then the diaphragm 23 will be moved towards the leftunder the increased vacuum suction in the diaphragm chamber, and thiswill cause the bar as, lever arm 19, and shaft 16 to bemoved towards theleft against the forceof the spring 18, moving the sensing head and gluenozzle towards the left until the orifices are at least partlyuncovered. In this way, any slight shifting of the position of the edgeof the traveling web causes the sensing head and the glue-applyingnozzle to shift their position correspondingly. In actual practice thelateral shifting of the webordinarily is very slight, never exceeding afraction of aninch, and consequently the resulting movements of thesensing head, shaft and glue-applying nozzle are very slight. However,with a rapidly traveling web these adjustmentsof position may occur inrapid succession, and this positioning control means, when properly setup and balanced,,is very sensitive and will respond to slight changesin-the position of the edge of the web with utmost speed.

As previously indicated, this positioning control means can be used forother operations on a traveling web which may require accuratemaintenance of a constant lateral spacing with respect to the edge lineof the web. However its most important and extensive use is believedtobe in th application of the narrow lineof adhesivefor the formation ofthe bag tubing in a bag making machine, as herein described.

We claim:

1. In an automatic positioning control for a device operating on atraveling web passing over guide rollers, a shaft extending parallel tothe guide rollers for said web, support means for said shaft, said shaftmounted for axial movement in said support means, said device operatingon the Web supported on said shaft, a lever arm connectedto said shaft,a diaphragm and a housing forming an airtight diaphragm chamber withsaid diaphragm, a link connecting said diaphragm with said lever arm tocause axial movement of said shaft with movement of saiddiaphragm, asensing head supported on said shaft, said sensing head positionedagainst said web and provided with an orifice arranged so as to benormally covered in part by an edge portion. of said web, an air hoseconnecting said sensing head with said diaphragm chamber,,said diaphragmchamber connected with air exhaust means, and spring means exerting aforce to move said shaft. in opposition to the force of said diaphragmunder vacuum pressure.

2. In an automatic positioning control for a device operating on atraveling web passing over guide rollers, a shaft extending parallel tothe guide rollers for said web, support means for said shaft, said shaftmounted for axial movement in said support means, said device operatingon the web supported on said shaft and laterally adjustable thereon, alever arm connected to said shaft, a diaphragm and a housing forming anairtight diaphragm chamber with said diaphragm, a link connecting saiddiaphragm with said lever arm to cause axial movement of said shaftwithmovement of said diaphragm, a sensing head supported on said shaftand laterally adjustable thereon, said sensing head positioned againstsaid web and provided with-an orifice arranged so as to be normallycovered in part by an edge portion of said web, an air hose connectingsaidsensing head with said diaphragm chamber, said diaphragm chamberconnected with air exhaust means exhausting the. air from said chamberat the same. rate; at which. airscanbe drawn into said chamber from saidsensing head when said orifice is partly covered by said web, and springmeans exerting a force to move said shaft in opposition to the force ofsaid diaphragm under vacuum pressure, whereby lateral movement of saidWeb with respect to said sensing head orifice will immediately result incorresponding movement of said shaft and therewith of said sensing headand said web operating device, and thereby maintain said web operatingdevice in desired predetermined position with respect to said edgeportion of said web.

'3. In an automatic positioning control for an applicator applying astrip of adhesive on a traveling web passing over guide rollers, a shaftextending parallel to the guide rollers for said web, support means forsaid shaft, said shaft mounted for axial movement in said support means,said adhesive applicator supported on said shaft, a lever arm connectedto said shaft, a diaphragm and a housing forming an airtight diaphragmchamber with said diaphragm, a link connecting said diaphragm with saidlever arm to cause axial movement of said shaft with movement of saiddiaphragm, a sensing head supported on said shaft, said sensing headpositioned against said web and provided with an orifice arranged so asto be normally covered in part by an edge portion of said web, an airhose connecting said sensing head with said diaphragm chamber, saiddiaphragm chamber connected with air exhaust means, exhausting air fromsaid chamber at the same rate at which air can be drawn into saidchamber from said sensing head when said orifice is partly covered bysaid web, a collar mounted on said shaft, and a coil spring on saidshaft held under compression between said collar and a bearing for saidshaft and exerting a force to move said shaft in opposition to the forceof said diaphragm under vacuum pressure, whereby lateral movement ofsaid web with respect to said sensing head orifice will immediatelyresult in corresponding movement of said shaft and therewith of saidsensing head and said adhesive applicator, and thereby maintain saidadhesive applicator in desired predetermined position with respect tosaid edge portion of said web. I

4. An automatic positioning control for an applicator applying a stripof adhesive on a traveling web of paper passing over guide rollers to apaper bag machine, said positioning control including a shaft extendingparallel to the guide rollers for said web, support means for saidshaft, said shaft mounted for axial movement in said support means, saidadhesive applicator supported on said shaft and laterally adjustablethereon, a lever arm connected to an end of said shaft, a diaphragm anda housing forming an airtight diaphragm chamber with said diaphragm, alink connecting said diaphragm with said lever arm to cause axialmovement of said shaft with movement of said diaphragm, a sensing headsupported on said shaft and laterally adjustable thereon, said sensinghead positioned against said web and provided with a plurality oforifices in alignment with the direction of travel of said web arrangedso as to be normally covered in part by an edge portion of said web, anair hose connecting said sensing head with said diaphragm chamber, saiddiaphragm chamber connected with air exhaust means exhausting air fromsaid chamber at the same rate at which air can be drawn into saidchamber from said sensing head when said orifices are partly covered bysaid web, a collar adjustably mounted on said shaft and a coil spring onsaid shaft held under compression between said collar and a bearing forsaid shaft and exerting a force to move said shaft in opposition to theforce of said diaphragm under vacuum pressure, whereby lateral movementof said web with respect to said sensing head orifices will immediatelyresult in corresponding movement of said shaft and therewith of saidsensing.

head and said adhesive applicator, and thereby maintain said adhesiveapplicator in desired predetermined position with respect to said edgeportion of said web.

References Cited in the file of this patent UNITED STATES PATENTS1,634,984 Dickhaut July 5, 1927 2,438,787 Nicholas Mar. 30, 19482,702,522 Speed Feb. 22, 1955

